https://docs.fd.io/csit/master/report/vpp_performance_tests/packet_throughput_graphs/l2-2n-tx2-xl710.html#b-1t1c-l2switching-scale-af-xdp

From this document, we can see the performance comparison between AF_XDP and DPDK. So why is AF_XDP's performance so low?

AF_XDP send and receive messages is zero copy, the performance should be similar to DPDK.